Related papers: Titanium hidden in dust
Supernovae have long been proposed to be efficient dust producers in galaxies. Observations in the mid-infrared indicate that dust forms a few hundred days after the stellar explosion. Yet, the chemical type and the amount of dust produced…
Recently, Elshamounty et al. performed a reanalysis of the surface temperature of the neutron star in the supernova remnant Cassiopeia A on the basis of Chandra data measured during last decade, and added a new data point. We show that all…
Dense, fast-moving ejecta knots in supernova remnants are prime sites for molecule and dust formation. We present SOFIA far-IR spectrometer FIFI-LS observations of CO-rich knots in Cas A which cover a ~1 square arc minute area of the…
The recent detection of a hard X-ray component in the supernova remnant Cassiopeia A is interpreted as synchrotron emission from electrons accelerated to energies up to 40 TeV (Allen et al., 1997). It is therefore tempting to consider TeV…
X-ray observations of the neutron star in the Cas A supernova remnant over the past decade suggest the star is undergoing a rapid drop in surface temperature of $\approx$ $2-5.5\%$. One explanation suggests the rapid cooling is triggered by…
We review the characteristics of nucleosynthesis and radioactivities in 'Hypernovae', i.e., supernovae with very large explosion energies ($ \gsim 10^{52} $ ergs) and their $\gamma$-ray line signatures. We also discuss the $^{44}$Ti line…
JWST observations of the young Galactic supernova remnant Cassiopeia A revealed an unexpected structure seen as a green emission feature in colored composite MIRI F1130W and F1280W images - hence dubbed the Green Monster - that stretches…
The radiosotope $^{44}$Ti is produced through $\alpha$-rich freezeout and explosive helium burning in type Ia supernovae (SNe Ia). In this paper, we discuss how the detection of $^{44}$Ti, either through late-time light curves of SNe Ia, or…
We consider a small sample of oxygen-rich, asymptotic giant branch stars in the Large Magellanic Cloud, observed by the Spitzer Space Telescope, exhibiting a peculiar spectral energy distribution, which can be hardly explained by the common…
Infrared continuum observations provide a means of investigating the physical composition of the dust in the ejecta and swept up medium of the Cas A supernova remnant. Using low resolution Spitzer IRS spectra (5-35 $\mu$m), and broad-band…
Objects of known brightness, like Type Ia supernovae (SNIa), can be used to measure distances. If a massive object warps spacetime to form multiple images of a background SNIa, a direct test of cosmic expansion is also possible. However,…
We present the results of extinction measurements toward the main ejecta shell of the Cassiopeia A supernova (SN) remnant using the flux ratios between the two near-infrared (NIR) [Fe II] lines at 1.26 and 1.64 $\mu {\rm m}$. We find a…
The surface of hot neutron stars is covered by a thin atmosphere. If there is accretion after neutron star formation, the atmosphere could be composed of light elements (H or He); if no accretion takes place or if thermonuclear reactions…
Over the previous millennium, only five Galactic supernovae were observed and recorded by contemporary astronomers, and their current-day counterparts subsequently identified. The remnants of four of these have all been very deeply studied,…
We present a deep X-ray observation of the young Galactic supernova remnant Cas A, acquired with the ROSAT High Resolution Imager. This high dynamic range (232 ks) image reveals low-surface-brightness X-ray structure, which appears…
At high energies, the hadronic origin of gamma rays from supernova remnants is still debated. Assuming the observed gamma-rays from the Wolf-Rayet supernova remnant Cas A are due to accelerated protons and ions, we predict the nuclear…
Titanium dioxide, TiO$_2$, is a refractory species that could play a crucial role in the dust-condensation sequence around oxygen-rich evolved stars. To date, gas phase TiO$_2$ has been detected only in the complex environment of the red…
Study of radio supernovae over the past 25 years includes two dozen detected objects and more than 100 upper limits. From this work it is possible to identify classes of radio properties, demonstrate conformance to and deviations from…
Cassiopeia A the youngest supernova remnant known in the Milky Way is one of the brightest radio sources in the sky and a unique laboratory for supernova physics. Although its compact remnant was discovered in 1999 by the Chandra X-Ray…
Core-collapse supernovae are considered to be important contributors to the primitive dust enrichment of the interstellar medium in the high-redshift universe. Theoretical models of dust formation in stellar explosions have so far provided…